A few years ago it was all quite simple - you took antihypertensive drugs to lower your blood pressure and 'statins' to lower your LDL-cholesterol; in either case, if they were successful, you reduced your risk of heart attack and stroke (provided you exercised, too!). We've noted before that statins can have other beneficial actions, in addition to their lipid-lowering effects (see links below). In the study summarized here, a statin was given to people with high blood pressure but with normal or even low cholesterol levels, and it still reduced the risk of coronary and stroke events.

What was done

The Anglo-Scandinavian Cardiac Outcomes Trial (ASCOT) was a large clinical study that compared two blood pressure lowering treatments. The patients, who were recruited from family practices, had to have at least 3 risk factors for cardiovascular disease to be included in the study.¹ As an add-on, the cardiac effects of atorvastatin, a statin drug, were compared with those of placebo (i.e. a sugar pill) in those who had total cholesterol levels of 250 mg/dL (6.5 mmol/L) or less. About half the patients in the entire SCOT study qualified for this part of the study.

There were just over 10,000 patients in the lipid-lowering part of ASCOT - 5,000 each given placebo or 10 mg atorvastatin, daily. The study was planned to run 5 years, but after an average of 3½ years the results were so impressive that the treatment was stopped.

What was found

The participants were mainly white (95%) and male (81%), with an average age of 63. Their average total cholesterol was 213 mg/dL (5.5 mmol/L), LDL cholesterol 131 mg/dL (3.4 mmol/L), and HDL cholesterol 50 mg/dL (1.3 mmol/L). At the end of 3½ years, atorvastatin had lowered average total cholesterol levels by 50 mg/dL (1.3 mmol/L), or 24%, with a corresponding lowering of LDL cholesterol (35%).

Blood pressure control during the study was the same in both the atorvastatin and placebo groups, averaging 138/80 mm Hg at the end of the study.

Non-fatal heart attacks plus fatal heart events were lower by 36% with atorvastatin, compared with placebo - this was a highly significant finding. Fatal and non-fatal strokes were lower by 27% in the atorvastatin group - also a significant effect.

These beneficial effects were not affected by the participant's lipid levels. And serious adverse effects were no more frequent in the atorvastatin than in the placebo patients. In particular, there was no increased likelihood of cancer or raised liver function test results.

Comment

The significant reductions in heart attacks and strokes were additional to those produced by good blood pressure control, and were clearly due to the atorvastatin medication, as all the study subjects were given blood pressure medication. This finding is even more remarkable as it doesn't seem to be affected by the cholesterol levels of the patients, which entered the study with average, or below-average, lipid levels.

A similar study to this one was done with another statin, pravastatin: the so-called ALLHAT study. In this case, the statin didn't prove to have a significant effect on heart attacks or strokes. In ALLHAT the patients were considerably older, and included more women and non-white patients than in ASCOT. Earlier, smaller studies have shown results that go in the same direction as ASCOT.

It seems that taking a statin is helpful in reducing risk in people with a variety of cardiac risk factors, not just elevated lipid levels. Lowering lipid levels is obviously beneficial across the whole range of serum cholesterol concentrations. Statins probably deserve to be prescribed more widely in clinical practice.